The point-scanned dual-axis confocal (PS-DAC) microscope has been shown to exhibit a superior capability to reject out-of-focus and multiply scattered light in comparison to its conventional single-axis counterpart. However, the slow frame rate (typically < 5 Hz) resulting from point-by-point data collection makes these systems vulnerable to motion artifacts. While video-rate point-scanned confocal microscopy is possible, a line-scanned dual-axis confocal (LS-DAC) microscope provides a simpler means of achieving high-speed imaging through line-by-line data collection, but sacrifices contrast due to a loss of confocality along one dimension. Here we evaluate the performance tradeoffs between a LS-DAC and PS-DAC microscope with identical spatial resolutions. Characterization experiments of the LS-DAC and PS-DAC microscopes with tissue phantoms, in reflectance mode, are shown to match results from Monte-Carlo scattering simulations of the systems. Fluorescence images of mouse brain vasculature, obtained using resolution-matched LS-DAC and PS-DAC microscopes, demonstrate the comparable performance of LS-DAC and PS-DAC microscopy at shallow depths.

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Computer modeling using the ray-tracing method has been used to simulate the grazing-incidence x-ray topographic images of micropipes in 4H silicon carbide recorded using the pyramidal (11−28) reflection. Simulation results indicate that the images of micropipes appear as white features of roughly elliptical shape, canted to one side or other of the g vector depending on the dislocation sense. Observed images compare well with the simulations, demonstrating that the direction of cant provides a simple, nondestructive, and reliable way to reveal the senses of micropipes. Sense assignment has been validated using back-reflection reticulography.

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